1. Field of the Invention
The present invention relates to a fluid control device, and more particularly, to a valve for controlling the flow of either liquid or gaseous media.
2. The Prior Arts
Conventionally, a valve has a single poppet to control the flow of media, such as a liquid, gas, or other material, through a passage. To stop the media flow, the valve is provided with a spring, pneumatic pressure, electro-magnet, electro-mechanical device, mechanical screw or mechanical lever to force the poppet to seal the passage.
An external force is needed to seal the passage. Therefore, the inventor investigates a valve that utilizes the media pressure to stop the media flow and seal the passage. Because of utilizing the media pressure, the external force for sealing the passage is minimized. Thus, the media flow can be precisely controlled by the valve.